Originally posted by pentaxk5 haha, I guess that makes me newbie of the newbie. joke of the day
now all I need is to find out what does it mean by mirror is up.
still, thanks all for the answers^^
SR and similar features from other brands are actually pretty energy-intensive functions. For that reason your camera will not engage SR until it's necessary to stabilize the sensor or to cancel out camera shake. As explained, this does not happen until the mirror locks up -- inside your camera in front of the sensor is a mirror which when down sends the image transmitted through your lens up into the prism and out through the viewfinder. In order to take a picture (or engage Live View on the LCD screen), the mirror has to get out of the way, and when it flips up SR turns on. When you turn on Live View the first thing you hear is the mirror slapping out of the way and then the continuous white noise is the SR, as others have mentioned.
I had an old point and shoot from Canon with image stabilization, and I remember the IS was constantly on. Naturally the battery life was
atrocious.